The present invention relates to an electrophotography apparatus such as an electrophotography printer including a laser printer and an electrophotography coping machine etc. and, more particularly, relates to an optional unit construction of an electrophotography apparatus having a transferring device.
In general, in a formation method of a color picture image in an electrophotography apparatus having an intermediate transferring body, an electrostatic latent image on a photoconductive body is developed according to respective developing devices and a developed toner image is transferred once on the intermediate transferring body and on the above that a color overlapping is carried out, after that to a paper sheet which has transported by a transporting device a color toner image on the intermediate transferring body is transferred in the lump and is formed.
As stated in above, in the color electrophotography apparatus having the intermediate transferring body, the toner image on the photoconductive body is transferred once to the intermediate transferring body from the photoconductive body, and further from the intermediate transferring body to the paper sheet two times transfer is carried out and then the picture image is formed. After that according to a fixing device the color toner image on the paper sheet is heated and fixed and the paper sheet is discharged outside of the color electrophotography apparatus.
Further, in a color electrophotography apparatus having a duplexer printing unit which enables duplex printing, it is common that after a first color toner image on a paper sheet surface (A face) is heated and fixed once by the fixing device, this paper sheet is reversed in the duplexer printing unit, and a rear face (B face) of the paper sheet is transported as a next printing face to a transporting device of the color electrophotography apparatus, and in a manner similar to the printing of the A face, the B face is printed.
Further, recently from a consideration of the environment, there is a tendency to provide for energy saving and when a standard for regulating the power saving (for example an energizer: it differs from the devices, for example, under a condition (a sleeping time) in which the device is not operated and provides for consumption electric power which is less than 45 W) is not obtained, then such device is not accepted in a market.
Up to now, in the color electrophotography apparatus, to drive a control device (mainly, a control board), an optical sensor, a display element etc., a voltage power source having 5 V is used, further, to the actuators such as a motor, a fan, a clutch, a solenoid, in a relation of a construction efficiency, a voltage power source of 25 V which is higher than 5 V is used, and in many cases the electrophotography apparatus has these different power sources.
In general, during the electric power saving time, since it is unnecessary to operate the apparatus, all actuators and the heater are presented to an "off" state, the electric power consumption is reduced. Further, a 24 V power source is presented to an "off" state.
However, in the power source having 5 V for driving the controlling device (including CPU), such a 5 V electric power source cannot be presented to an "off" state. However, the components of the sensors, which in many cases are constituted by the above stated 5 V power source, are operated and further nevertheless during the electric power saving mode time it is required to leave the displaying device operational for informing the condition of an operator from aspects to a safety performance and a function performance.
Further, when the duplexer printing unit and a sorting device etc. which are optional units are added to the color electrophotography apparatus which is a main body, it is a rare case in which there is not an increase in the consumption energy having each optional unit part, but it is necessary to obey a regulated electric power saving standard as a system including the optional units.
On the other hand, when with only the color printing to the electrophotography apparatus main body there is afford for opportunities to achieve the electric power saving regulation value, it is devised to improve the consumption electric power reduction of the electrophotography apparatus main body. However, there is a case in which only the optional units themselves consumes much energy, there is a limitation to connect all optional units and to obey the electric power saving standard.
As stated above, in the conventional color electrophotography apparatus, there is a problem in which the electric power saving regulation is not satisfied fully.